Sadly the two are related. Your physiology affects you psychology and
the converse. The usefulness of drugs probably indicates that the
airsickness starts as a phisiological problem, but my own experience is
that it is exacerbated by tension, ie, the fear of getting airsick. For
those who prefer not to be drugged while PIC, there are, in fact, a
number of methods to reduce the additive physiological effects of
psychological tension. I am aware of the Alexander Technique. I'm sure
there are others.

If you have difficulty imagining this relationship, consider stage
fright. The symptoms are almost identical to motion-initiated nausea.

A question for those who get airsick... after vomitting, do the
symptoms ease? Or does the nausea remain?